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doc: update camera_manipulation example project and docs

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This commit is contained in:
Nick Fisher
2024-10-23 14:36:26 +08:00
parent bf02406bf4
commit 3dcacfe631
2 changed files with 73 additions and 12 deletions
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38
docs/camera_manipulation.mdx
View File

@@ -16,14 +16,48 @@ This will generally wrap a `ThermionWidget`, meaning the entire viewport will ac
Positioned.fill(
child: ThermionListenerWidget(
inputHandler:
DelegateInputHandler.fixedOrbit(_thermionViewer!),
DelegateInputHandler.fixedOrbit(_thermionViewer!)
..setActionForType(InputType.MMB_HOLD_AND_MOVE, InputAction.ROTATE)
..setActionForType(InputType.SCALE1, InputAction.ROTATE)
..setActionForType(InputType.SCALE2, InputAction.ZOOM)
..setActionForType(InputType.SCROLLWHEEL, InputAction.ZOOM),
child: ThermionWidget(
viewer: _thermionViewer!,
))),
]);
```
`ThermionListenerWidget` is a very simple widget; it simply forwards pointer, gesture and keyboard events to an instance of [InputHandler] that you provide.
`ThermionListenerWidget` is a very simple widget; it simply forwards pointer, gesture and keyboard events to the provided [InputHandler], which must decide how to interpret those events.
For example, one [InputHandler] implementation might interpret mouse pointer movement as "rotate the camera", whereas a separate implementation might interpret it as "translate this specific entity".
Thermion provides two default InputHandler implementations for manipulating the camera: [DelegateInputHandler.fixedOrbit] and [DelegateInputHandler.flight].
[DelegateInputHandler.fixedOrbit] will rotate the camera in a fixed orbit around a target point (the origin, by default), and also allow zooming in/out (subject to a minimum distance, which is configurable).
By default, [DelegateInputHandler.fixedOrbit] will:
- rotate the camera when the middle mouse button is held and the pointer is moved (on desktop), and when a single swipe left/right/up/down is detected (on mobile)
- zoom the camera when the scroll wheel is scrolled up/down (on desktop), and when a pinch gesture is detected (on mobile)
You can change the action for a specific input type by calling `setActionForType`; for example, if you wanted to rotate the camera by moving the mouse pointer while holding the left mouse button, you would call:
```
setActionForType(InputType.LMB_HOLD_AND_MOVE, InputAction.ROTATE)
```
See the [InputType] and [InputAction] enums for available input types and actions.
[DelegateInputHandler.flight] will translate keyboard and mouse/touchscreen gestures to free flight camera manipulation.
By default:
- holding the middle mouse button will control the pitch/roll/yaw of the camera
- holding the left mouse button will pan the camera left/right/up/down
- the middle mouse button will zoom/dolly the camera in/out
- the WASD keys will pan the camera left/right/up/down and dolly the camera forward/backward
If these don't exactly fit your use case, you can create your own [InputHandler] implementation. If you think it would be useful to other users, please feel free to submit a PR for your implementation to be included in the base Thermion package.

47
examples/flutter/camera_manipulation/lib/main.dart
View File

@@ -36,6 +36,9 @@ class MyHomePage extends StatefulWidget {
class _MyHomePageState extends State<MyHomePage> {
late DelegateInputHandler _fixedOrbitInputHandler;
late DelegateInputHandler _freeFlightInputHandler;
@override
void initState() {
super.initState();
@@ -48,27 +51,51 @@ class _MyHomePageState extends State<MyHomePage> {
await _thermionViewer!.setPostProcessing(true);
await _thermionViewer!.setRendering(true);
_fixedOrbitInputHandler =
DelegateInputHandler.fixedOrbit(_thermionViewer!)
..setActionForType(InputType.MMB_HOLD_AND_MOVE, InputAction.ROTATE)
..setActionForType(InputType.SCALE1, InputAction.ROTATE)
..setActionForType(InputType.SCALE2, InputAction.ZOOM)
..setActionForType(InputType.SCROLLWHEEL, InputAction.ZOOM);
_freeFlightInputHandler =
DelegateInputHandler.flight(_thermionViewer!)
..setActionForType(InputType.MMB_HOLD_AND_MOVE, InputAction.ROTATE)
..setActionForType(InputType.SCALE1, InputAction.ROTATE)
..setActionForType(InputType.SCALE2, InputAction.ZOOM)
..setActionForType(InputType.SCROLLWHEEL, InputAction.ZOOM);
setState(() {});
});
}
ThermionViewer? _thermionViewer;
bool isOrbit = true;
@override
Widget build(BuildContext context) {
return Stack(children: [
if (_thermionViewer != null)
if (_thermionViewer != null) ...[
Positioned.fill(
child: ThermionListenerWidget(
inputHandler:
DelegateInputHandler.fixedOrbit(_thermionViewer!)
..setActionForType(InputType.MMB_HOLD_AND_MOVE, InputAction.ROTATE)
..setActionForType(InputType.SCALE1, InputAction.ROTATE)
..setActionForType(InputType.SCALE2, InputAction.ZOOM)
..setActionForType(InputType.SCROLLWHEEL, InputAction.ZOOM) ,
child: ThermionWidget(
viewer: _thermionViewer!,
))),
inputHandler: isOrbit
? _fixedOrbitInputHandler : _freeFlightInputHandler,
child:ThermionWidget(
viewer: _thermionViewer!,
))),
Column(
mainAxisAlignment: MainAxisAlignment.end,
children: [
ElevatedButton(
onPressed: () {
isOrbit = !isOrbit;
setState(() {});
},
child: Text("Switch to ${isOrbit ? "Free Flight" : "Orbit"}"))
],
)
],
]);
}
}